Verification of improved shield control algorithm by site data
The shield control algorithm had been developed by using the kinematic shield model. In this algorithm, jack forces, i.e., jack thrust, jack horizontal moment, and jack vertical moment, are optimized so as to minimize the deviation from the planed alignment to the simulated shield position. In this research, the shield control algorithm was improved, based on the existing algorithm. Furthermore, the improved algorithm applied to the site data and the performance of it was examined by comparing the calculated jack forces with the measured jack forces.
As a result, the followings are made clear: 1) The improved control algorithm could provide the optimum jack forces to follow the planed alignment in case of steady state. 2) When the initial position of shield is shifted from the planed alignment, it is necessary to set the alignment for correction to get the preferable jack forces.